In this work, new doped Nafion membranes with enhanced proton conductivity were prepared to be used as proton exchange membranes in fuel cells. New dopants derived from arylmono- or bisphosphonic acid were prepared and incorporated into the new membranes using impregnation or casting methods. Pr...

A selective one-pot procedure of synthesis of 1-hydroxymethylene-1,1-bisphosphonic partial trimethylesters and P,P-, P,P′-diesters was described.

Two suitably protected derivatives of phosphoserine 1 have been prepared in which the regular ester-oxygen is replaced by either a hydroxymethylene moiety or by a phosphorylated hydroxymethylene moiety. The second derivative termed ‘phosphate phosphonate’ 3 yields the hydroxymethylene phosphon...

A simple and efficient one-pot procedure for synthesis of 1-hydroxymethylene-1,1-bisphosphonic acids by reaction of acyl chlorides and tris(trimethylsilyl)phosphite is described. This method was applied to the synthesis of new phosphonated chelating tripod ligands.

The Lewis acid-promoted coupling reactions of (5R, 6S)-2-acetoxy-4-(benzyloxycarbonyl)-5,6-diphenyl-2,3,5,6-tetrahydro-4H-1,4-oxazines (11a-e, and 21), which are prepared easily from (+-(5R, 6S)-4-(benzyloxycarbonyl)-5,6-diphenyl-2,3,5,6-tetrahydro-4H-1,4-oxazin-2-one (9), with allyltrimethylsil...

Tartrate dehydrogenase catalyzes the reductive decarboxylation of meso-tartrate to glycerate. Concomitant with the ketonization of the intermediate enolate the C3 hydroxymethylene of glycerate necessarily acquires a proton from solvent. In D2O, the proton is shown to be added stereospecifically ...

The hydroxymethylene cation (HCOH+) is believed to be chemically independent of the more stable formaldehyde cation isomer in interstellar chemistry and may likely be a precursor to methanol in chemical reaction networks. Previous work is corroborated here showing that the trans conformer of HCO...

During a recent investigation of the photophysical properties of Ru(II) complexes containing the ligand 4,4′-bipyridine we had occasion to prepare an intermediate, 1,4-bisethoxymethylene-2,3-butadione, abbreviated as EMB. We were surprised to find a strong band at ca. 1590 cm−1 (IR spectra) whi...

The synthesis of various substituted 2-pyridyl-5-cyano-pyrimidine-6-ones was accomplished via a three-step protocol. The key aspects of this parallel protocol was the preparation of amidines from nitriles under mild conditions followed by cyclization with ethyl (ethoxymethylene)cyanoacetate.

(E)-N′-(Ethoxymethylene)hydrazinecarboxylic acid methyl ester was synthesized in one step in good yield. This reagent was successfully applied to the one-pot synthesis of 4-substituted 2,4-dihydro-3H-1,2,4-triazolin-3-ones from readily available primary alkyl and aryl amines. This reaction proc...

New derivatives of 1-[(1-ethoxymethylene)amino]imidazol-5(4H)-one and 1,2,4-triazin-6(5H)-one were synthesized via reactions of optically active α-aminocarboxylic acid hydrazides and triethyl orthoesters in xylene. The factors influencing the formation of the unexpected five-membered products a...

2-Ethoxymethylene-3-oxobutanenitrile is a versatile trifunctional reagent that allows the introduction of a three-carbon moiety to amine-substrates. The reaction of the title compound with hydrazines has been studied leading to appropriate substituted pyrazoles 4–11. Reactions with other dinitr...

The reaction between ethyl(ethoxymethylene)cyanoacetate and 5-phenoxymethyl-2-amino-2-oxazoline leads to a 1,4-adduct and to a 2,3-dihydrooxazolo[3,2-a]pyrimidin-5-one. The structures were assigned by spectroscopy and, for the cyclocondensation compound, by X-ray crystallography. The question of...

4-Ethoxymethylene-2-[1]-naphthyl-5(4H)-oxazolone 1b was synthesized from 1-naphthoyl-glycine and triethyl orthoformate as a fluorescent analogue of the hapten 4-ethoxymethylene-2-phenyl-5(4H)-oxazolone. A simple and general method has been devised to prepare conjugates of type 6 between 1b and a...

The palladium-catalysed reaction of isoprene with methanol yields methoxy dimethyl octadienes (“methoxy dimers”) and dimers of isoprene. To obtain additional information about the mechanism of catalysis this paper is aimed at identifying the higher boiling side-products of this reaction. After...

Preparation properties and reactions of the title reagent are reported. The reagent is potentially useful for cross-linking proteins and/or nucleic acids.

The IR and Raman spectra of methoxymethylene-propanedinitrile [H3COCHC(CN)2] and 1-methoxyethylidene-propanedinitrile [H3COC(CH3)C(CN)2] as a solid, liquid and solute in various solvents have been recorded in the region 4000-50 cm−1. NMR spectra of both compounds in various solvents ...

The inverse electron demand hetero-Diels-Alder reaction of methoxymethylene substituted 1.3-dicarbonyl compounds with enol ethers and enediol ethers results in the selective formation of 3.4-dihydro-2H-pyrans. These adducts with a high density of functional groups are versatile intermediates for...

The IR (4000–400 cm−1) and Raman (4000–50 cm−1) spectra of 3-methoxymethylene-2,4-pentanedione (H3C–O–CHC(COCH3)2) in the liquid and solute forms in various solvents of different polarity were recorded at ambient temperature. Additional IR and Raman spectra were obtained for amorphous and cr...

Whereas Li(t-Bu) is an efficient base for the generation of Ph3PCHOMe, Li(n-Bu) gives both this ylide and a butylidene ylide which is consistent with a Ph2(MeOCH2)PCH(n-Pr) formulation. 13P NMR studies and their reactions with acylsilanes are described.